+23251 f(x) = 2 is a constant function.
It's constant, because the answer, the y-value, the f(x) value, is always 2.
It makes no matter what you replace for x, the answer is always 2. Since this never varies, it is a constant.
It's a function because there is always one value for f(x), no matter what you replace for x.
The value for f(x) doesn't always have to be the same answer, as in this case; there just can't be more than one answer for each replacement of x.
